These are sub charge harnesses built to work with EP3 and RSX K20a engine harnesses (but may also work with others).
This sub charge harness will plug into your OEM engine harness and provide you with the plugs needed for the alternator and knock sensor. Make sure and select whether you are using a large or small plug knock sensor in the options below.
You will need to add your own battery cables from the starter and alternator to fit your chassis needs as they are not provided.